Shipping Update and a note about AIS

Those of you trying to follow the progress of M/V Trinityborg will have noticed that she's been off the coast of Taiwan for several weeks now. This, of course, isn't actually the case but illustrates one of the limitaions of AIS. More on that in a moment, but first an update.

We get fowarded an email sent from the shipper to PAE with the latest update on Trinityborg. The latest read:

01/January/2014 – noon  (24 :00hrs UTC)

20*39.0 N  -  171*21.2 W

wind : W-3  -  sea-state : slight – swell: W 0,5m

speed: 14.6 knots

distance run last 24hrs: 349,6 miles -  distance to go Balboa 5541 miles

eta Balboa 17/Jan/2014 PM

eta Port Everglades 25-26/Jan/2014

That puts her a few hundred miles west of Hawaii:



Link to full map

AIS Limitations

Which brings us neatly to the limitations of AIS. Without going into too much detail, AIS is a system by which ships can broadcast their position, speed, and other details over VHS radio. In order to be able to receive this signal, the receiver must be within line of sight of the ship's antennae and have an receiving AIS system. In addition, in order to show up on the various websites, they must also share the AIS data they receive somehow.

For a ship the size of Trinityborg and a ground based antennae, line of site is probably not much more than 30 miles. This assumes that both sending and receiving antennae are 100 feet off the ground and that the sending radio is powerful enough for the receiving antenna to hear. 

We were hoping that that would happen near Hawaii, but apparently not.

I assume that the ship has been sending positional data to headquarters using satellites - radio or internet - which is how they know the details they know. AIS does not transmit wind or sea state.

I'll post up updates as we get them.